Bovine Neonatal Pancytopenia - correlation between clinical symptoms, hematological parameters and lifespan

To compare the hematological parameters and clinical symptoms between Bovine Neonatal Pancytopenia (BNP) diseased calves dying before and after 14 days of life.

Clinical observations included 47 calves from dams which underwent a 3-year vaccination program with the inactivated PregSure^® BVD vaccine. In 25 of these 47 BNP affected calves blood examinations were performed and in 22 dead calves diagnosis was mainly based on post-mortem findings.

Cutaneous bleeding was the predominant clinical manifestation in 32 from 47 calves (68.1%). Seven from 47 calves (14.9%) developed cutaneous bleeding as the only symptom and 17 from 47 calves (36.2%) demonstrated these alterations in combination with hemorrhagic lesions of the oral mucosa. In 66.0% (31/47) of calves petechiae of the oral mucosa were seen and petechiation without any other BNP related symptoms occurred in eight from 47 calves (17.0%). The hematological analysis revealed thrombocytopenia in all 25 cases (n = 23: PLT < 60 x 10⁹/l, n = 2: PLT 139-164 x 10⁹/l). Nineteen from 25 calves (76.0%) developed thrombocytopenia and leukocytopenia (WBC < 3.5 x 10⁹/l). In nine of them a decrease of erythrocyte count (RBC < 4.5 x 10⁹/l), hemoglobin concentration (Hb < 8 g/dl) and packed cell volume (PCV < 24%) was measured. Three BNP affected calves without clinical symptoms were identified by hematological examination. The average life time of BNP affected calves was 14.7 ± 6.2 days. Clinical findings, especially multifocal cutaneous hemorrhages were more frequently recognized in calves living longer than 14 days.

At the time of falling ill with BNP, older calves displayed more numerous symptoms, especially bleeding in the skin. Thrombocytopenia and erythropenia occur as well as a decreased hemoglobin concentration and a low PCV. The time between outbreak of symptoms and death of calves which fell ill later, did not differ from the survival time of BNP calves, which displayed symptoms at a younger age. A decrease of thrombocytes was the cardinal laboratory finding.